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Functional imaging studies have identified a matrix of structures in the brain that respond to noxious stimuli. Within this matrix, a division of function between sensory-discriminative and affective responses has so far been demonstrated by manipulating either pain intensity or unpleasantness under hypnosis in two different normal volunteer groups studied(More)
OBJECTIVE To determine the effects on the laser evoked potential (LEP) of selectively attending to affective (unpleasantness) versus sensory-discriminative (localisation) components of pain. METHODS LEPs, elicited by painful CO2 laser stimulation of two areas of the right forearm, were recorded from 62 electrodes in 21 healthy volunteers, during three(More)
OBJECTIVE Functional neuroimaging studies have shown that experimentally induced acute pain is processed within at least 2 parallel networks of brain structures collectively known as the pain matrix. The relevance of this finding to clinical pain is not known, because no direct comparisons of experimental and clinical pain have been performed in the same(More)
This study investigates the effects of noise distraction on the different components and sources of laser-evoked potentials (LEPs) whilst attending to either the spatial component (localisation performance task) or the affective component (unpleasantness rating task) of pain. LEPs elicited by CO2 laser stimulation of the right forearm were recorded from 64(More)
Electrophysiological studies have revealed a source of laser pain evoked potentials (LEPs) in cingulate cortex. However, few studies have used realistically shaped head models in the source analysis, which account for individual differences in anatomy and allow detailed anatomical localisation of sources. The aim of the current study was to accurately(More)
OBJECTIVES To (i) accurately localize the cingulate source of late laser evoked potentials (LEPs) using a realistic head model incorporating the individual's anatomy and (ii) assess the within-subject reproducibility of this source. METHODS Late LEPs, elicited by painful CO2 laser stimulation of the right forearm, were recorded from 62 electrodes in one(More)
We investigated whether the perception of simultaneity for pairs of nociceptive and visual stimuli was dependent upon the focus of participants' attention to a particular sensory modality (either pain or vision). Two stimuli (one painful and the other visual) were presented randomly at different stimulus onset asynchronies (SOAs) using the method of(More)
Experimental placebo analgesia is induced by building an expectation of reduced pain in a specific body part, usually using an inert cream in the guise of a local anaesthetic in conjunction with conditioning. We investigated non-site-specific placebo analgesia by conditioning subjects to expect the anaesthetic cream on one arm, without specifying if they(More)
Laboratory research suggests that the processing of painful stimuli can be modulated by selective attention to a particular sensory modality. However, alternative accounts for previous findings remain possible in terms of task-switching and spatial attention effects. In the present study, we examined whether attention can be selectively directed to the pain(More)
Nociceptive processing within the human brain takes place within two distinct and parallel systems: the lateral and medial pain systems. Current knowledge indicates that the lateral system is involved in processing the sensory-discriminative aspects of pain, and that the medial system is involved in processing the affective-motivational aspects of pain.(More)